Presently existing optical networks include optical-to-electrical-to-optical (OEO) conversion at many points. A typical wavelength switch used today converts the input light signal into an electronic signal to detect the routing information, switches the electronic signal, and then eventually reconverts it back into a light signal for further transmission. This device, commonly referred to as an Optical-Electrical-Optical (OEO) switch, not only depends on current semiconductor technologies and processes, but also requires a transmitter and a receiver for each transmission port. These factors cause OEO switches to be large in size, to have high power consumption in the range of kilowatts, to be network protocol and transmission rate dependent, to lack scalability, and to be costly.
All-optical networks encounter issues of aggregating and disaggregating communication channels. Power combiners may be used to aggregate channels, but have the inherent problem of introducing high loss as channels are aggregated. Overcoming losses with all-optical amplifiers introduces noise. This issue is exacerbated as networks are scaled to larger sizes and denser frequencies, from systems with 32 optical channels with 100 GHz channel spacing, through 128 channel systems with 25 GHz channel spacing. This trending towards denser and denser frequencies is expected to continue as systems expand beyond the existing use of C-band into L-band.
Therefore, what is required is a method or system which would allow the network to establish photonic connections without the necessity of intermediate OEO conversion yet also allow effective scaling of the network to larger and larger networks.